Melanocetus johnsonii has a wide horizontal distribution in tropical and subtropical waters of all three major oceans of the world between approximately 55°N and 45°S. Compared to its congener M. murrayi, it appears to occupy relatively shallow depths: about 62% of the material (for which data are available) was captured by open nets fished at maximum depths of 1000 m; 82% of the material can be accounted for by gear fished above 1500 m, and 98% by gear fished above 2100 m.